- "Vader's set up a special assassination unit of former Republic commandos and ARCs within the Five-oh-first solely to hunt Jedi, deserters and sympathizers."
- ―Mereel Skirata
The Imperial Commando Special Unit was a special forces division of elite operatives that formerly belonged to the Republic Grand Army's Special Operations Brigade during the Clone Wars. With roughly a thousand commandos left by the end of the conflict, the remaining squads were reorganized as a special division within the 501st Legion, the personal stormtrooper unit that served directly under the command of the Sith Lord Darth Vader.
During the early period of the New Order, the Imperial commandos were often tasked with assignments that involved hunting down and assassinating the enemies of the Galactic Empire, ranging from fugitive Jedi to clone renegades and deserters. The unit was first commanded by the Emperor's Hand Sa Cuis, but was later replaced by Commander Roly Melusar after his death. The first Imperial commandos included three of the four members of Delta Squad: IC-1138, IC-1140 and IC-1262; RC-1207 had disappeared in the line of duty. The commandos left over from Omega Squad and Galaar Squad were merged into Squad 40.
- "Your former special forces comrades are adept at causing death and chaos. So you are the ones best placed to locate and neutralize them. I expect no quarter given to them. They were your brothers once, but they are now traitors, an insult to all of you and your sacrifices. You are now the Imperial Commando Special Unit. Do not disappoint me."
- ―Darth Vader, to the Imperial commandos
The New Order's first Imperial commandos were the Republic commandos of the Grand Army's Special Operations Brigade. With the end of the Clone Wars immediately followed by the rise of the Galactic Empire in 19 BBY, the remaining commandos were transferred to the 501st Legion, an elite stormtrooper unit under the command of the Sith Lord Darth Vader. Known collectively as the Imperial Commando Special Unit, the new organization remained comprised of genetically-identical soldiers, bred from the same clone line that produced the Republic clone troopers. Nearly everything else about the commandos—their armor, designations and even their squads—were altered to reflect the Empire's policy of Imperialization.
The Imperial commando ranks did not reflect the full strength that the former Special Operations Brigade started with at the beginning of the Clone Wars. In addition to several confirmed deserters, attrition due to three years of civil war inflicted heavy casualties on them, leaving the Empire to inherit roughly a thousand clone commandos by the end of the conflict. In addition to the millions of new clone soldiers that swelled the ranks of the Stormtrooper Corps, Arkanian Microtechnologies produced Spaarti-engineered clones for the purpose of replenishing the commando ranks. The original commandos that were bred via Kaminoan techniques were secretly agitated by the introduction of clones from the Arkanian batch of Centax-2, whom they regarded as subpar troopers with inferior training. Though the former Republic commandos composed the vast majority of the Imperial Commando Special Unit, a number of Alpha-class ARC troopers were also recruited into the 501st ranks to train new generations of the Empire's elite shock troopers.
In the days that followed Emperor Palpatine's rise to absolute power, the commandos replaced their old Katarn-class armor for a new suit of armor, devoid of unit markings and personal customizations in accordance with the New Order's emphasis on uniformity and obedience. Squads that had suffered one or more losses were either given new replacements or combined with other squads. The former Delta Squad's RC-1207 was replaced by a new commando; the remaining members of Galaar Squad and Omega Squad were amalgamated to form Squad 40. However, their identification numbers, apart from the IC prefix, remained the same. In addition to retaining the same designations, the commandos were permitted to keep the DC-17 rifle for a time, mostly because it was the primary weapon that they were accustomed with.
Though overall command of the unit fell to Darth Vader, Imperial commando operations were more closely monitored by a subordinate of the Dark Lord of the Sith. Their first commander was the Dark Jedi Sa Cuis, a Force-sensitive assassin known as an Emperor's Hand. After Cuis's death, leadership of the Imperial commandos reverted to an Imperial officer named Roly Melusar.
- Order 66: A Republic Commando Novel (First appearance)
- Darth Vader and the Lost Command 1
- Imperial Commando: 501st
- Star Wars: The Force Unleashed video game (Non-canonical appearance)